/Engine/Source/Runtime/ApplicationCore/Public/GenericPlatform/Accessibility/GenericAccessibleInterfaces.h
Set the value stored by the widget. While this function accepts a String, there is no way to know what the underlying data is stored as. The platform layer must retain some additional information about what kind of widget this is, and ensure it's being called with valid arguments.
virtual void SetValue ( const [FString](API\Runtime\Core\Containers\FString) & Value )